Lifting-magnet.



No.- s35,942. PATENTBD No'v. Isl ma."

APPLICATION 'FILED AUG. 30. 1905. 4

2 suivra-snm* 2L T all whom ,L't., may concern."

.Application filed August 30, 1905. Serial No. 276.418. 'l I .1.. 1

Be it 4known that I, ARTHUR C. EAsTwooD, a citizen of the United States, residing i-n Cleveland, Qhio, have invented certain Imrovements in Lifting-Magnets, of which the ollowing is a specification.

Theo jectiof my .invention is to provide a magnet for the lifting and transportation of articles ofsteel or iron-such as pig or scrap iron, bolts, nuts, nails, turnin s, &c.of .auch construction that itsweig t shall be relatively small proportionatelyr to the Weight of the loador the body of material llifted by it.

This object I attain as hereinafter set forth, reference being had Ato the accompanyindrawings, in whichigure l is a vertical section of one fornrof my invention, -illustrating one construction .of framework whereby `the above-noted objects ma'y be secured. Fig. 2 is an inverted lanview of' the magnet shown. in Fig. 1. ig.` 3 is a vertical section of a magnet in which the central pole-piece .hasbeen. omitted and the central part of the frame hollowed. Fig. 4 is a vertical section of a lifting-magnet in which the central pole-piece, as well as the center of the frame, has been made hollow, in addition to which the frame 'has been .constructed 1with but -a relatively small annularpo'lelpiece; and Fig. 5V is a vertical section of a form of magnet in which the aniular polefpiece has been altogether omit- -te So far as I am aware prior to my invention of the lifting-magnet shown and described in United States Patent No. 7 94,086, granted t0' me July4, 1905, the load to be lifted constituted onlyV the armature of the lifting- .magnets -hitherto known to the art, it being lconsidered necessary to bring portions of the 'magnet into intimate contact with the load -of.ma

etic material to be lifted. If the core' o anelectromagnet be defined as that por,tion of a magnetic circuit which is within the magneti-zi'n-coil, then inthat form of liftin magnet escribed in my above-mentione patentit will be noted that the load of magnetic material to lie-lifted constitutes notl in-1y the armature of the magnet, but i According to my'present invention I carry 'this idea stil farther and so design the magnet that the load'to 'be `lifted constitutesa relatively large POE ion of the 'magnetic circuit, attaining this tby hollewing the central c ore, by omit-- ting it altogether, by hollowing the centero the frame, or by partly or wholly omitting the annular pole-piece of the magnet. By this means it will be seen that I am enabled to construct a relatively powerful magnet,

which, however, is of but small weight compared withthe weight of the material which it is capable oi lifting.

In Figs. l and 2 oitlfe above drawings, A represents the `iron or steel frame of one form of my improved lifting-magnet, which may be described as'consisting of a supportingframe, from which project downwardly a central pole-piece (L and an annular polepiece a in such manner as to form between them an annular recess, in which is contained the magnet-winding B, this latter being held in place by a ring-shaped plate b, screwed or bolted in position, as desired.

`The central polepiece a in the present' in stance is recessed or hollowed, so that the amount of material in it is less than would be required for the magnetic circuit ofthe wind-` ing B. This recess may be of rectangular section, as shown in Fig. 2, or of circular section, and it will be understood that the'frame of the magnet may be of rectangular shape, as shown in said figure, or of circular form, without departing from my invention. Under operating conditions if this magnet be used to lift and transport borings or turnings bolts, nuts, nails, :or other relatively smali pieces of steel or iron such material will be drawn into the recess of the central pole as well as held to the brass cover-plate between the central and annular pole-pieces, andibecause of said recessed pole-piece a space will be provided for the reception of a greater body of material than could be handled if Vthis were a solid. At the same timethe similar in construction to that shown in Fig. 1.

In Fig. 4 I have shown a form ot my invention in which the frame A3' has the central pole-piece made with a recesso? in its The outer pole a in thiscase' is llO V65 magnet' consisting of a frame including a lower face and a second recess a4 in its upper face. In this form ofmagnet I soarrange vthe winding that the number of its turns decreases from the center outwardly and omit4 5all but a very small portion of the annular pole-piece a. With such' a construction I employ an outwardly-convex ring b2 of nonmagnetic material situated between the edge of lthe central pole-piece and the annular po e a In its ultimate form the magnet might' be `made as shown in Fig.` 5, there being in such case'merely a disk A of iron or steel serving as the su ortingframework, to Which the winding is held by means of a brass casing b3, consisting of an annular portion, from the lowerl edge of which there extends inwardlyand upwardly a rustconical portion. It will be seen that this magnet is particularly adapted for use for the transportation of fine -divided material, which When the coil is energized is not only drawn into the interior of the Winding-JL. e., Within the casing IIL-but is also held to the outside or ring p0rtion of the casing in such manner that it takes the place of the annular pole-piece ein# plo ed in the other forms of my invention, an so completes the magnetic circuit of the Winding.

It is essential that the reluctance of the magneticcircuit of a ma net for lifting bulk magnetic material be h ig before the attachment of a load and be materially reducedy by the addition of the load The more incom plete thel magnetic circuit of the magnet the igher Will be its reluctance and the less iron or steel will be required in its construction. Consequently its Weight Will be less, and if the material to be lifted can be made to form 'a relatively large portion oft-he magnetic circuit of the Winding a larger Weight of it' ma be lifted by a magnet of given Weight. ItT Will therefore be seen that bymeans of my invention the Weight of a ma net compared with the Weight of material vv ich it will lift is reduced in a compound-ratio.- 7

VI claim as my invention#- 1^. A magnet constituting a complete arti cleof-manufacture and constructed for-the simultaneous transportation ofa number4 of detached pieces oli-magnetic material, said magnet consisting of'a late of magnetic material, an annular Win ing held to the under side thereof, and an inclosing o'asing'for such Winding, the sameconsisting of a shell of non-ma netic material extending from the plateI within the windinj -to and around the owermost portion of'sai Winding, said plate having'a recess in the center of itsunder side, substantially as described.

.. 2. A magnet constituting-a complete article of manufacture and constructed for' the simultaneous transportation of a number of detached-pieces of magneticmaterial, said plate of magnetic material having a winding carried on its under side, and a casing of nonmagnetic material for the Winding, said casing having a frusto-conical portion extending inside said Winding and being provided 7o with a cylindrical iiange portion. extending around'the outside thereof, W'th means-for holding the casing to the plate, substantially as described.

3. A magnet constituting a complete arti- 7 5 cle of manufacture and' constructed` for the simultaneous transportation of a number of detached pieces of magnetic material, sind magnet consisting of a plate-of magnetlic-ma? terial having a central pole-piece,a-Windng 8o extending around said pole-piece', and means for holding said Winding in lace, thepolepiece .beingcut away so that its area of cross-- section is less than that roperly requiredfor the magnetic circuit of t e Winding3 substanl 8 5 tially as described. 0

` 4. A magnet constituting a complete' article of manufacture .and constructed for the simultaneous transportation of a number of vdetached pieces of magnetic material, said 9o magnet consisting `of a frame includinga plate of magnetic material having acentral pole-piece, a Winding extending around said pole-piece, and a metallic casinglield to the plate for maintaining thewinding in position:7 95 i said casingextending inside the Winding and around the outsidel edgez thereof substantially as described.l Y

5. A magnet constituting a complete artiL 1 cle of manufacture and constructed for? the. rco;

simultaneous vtransportation of anumber of detached pieces of magnetic material",` saidv magnet consisting of a plate of magnetic-.mafterial having a central polefpie'ce, awinding extending around said pole-piece, andV af casm5 ing held to the late for maintaining thel Winding in position, said casingl extending" inside lof the Windin and around tlie outside edge thereof, and'v t e 'ole-piece being cut. away so that itsarea o cross-sectongis-less ire A thanthat properlyrequired fortliemagnetic circuit of the Winding, substantiallyas deL scribed. -1

6. A magnet consistingof a complete arti f cle of manufacture and: constructed for the -115 simultaneous transportation of a numberl of detached pieces Otmagnctic' materiali, said vmagnet consisting/cfasubstantiallyjflatpiate of magnetic material, a winding projecting from one face' thereof, the-magnetic circuit of frac the Windi-ng bein open 'and substantially ini-v .5 complete on oneI -ace and its outersside, sub'- stantially as described.

7. A magnet consisting of'a complete:ar-tief cl'e of manufacture and constructed for' the '125 simultaneous .transportation of afnumberof" detached pieces' of" magnet-)icA maserial", said.' magnet consisting ofa body' onragneticmaj terial: and-an annular su gorted so' as to project from eneofxsaiff4 'odfthe central portion of the bodybeing recessed in order tovccncentrate the magnetic ux and forming a pole-piece for the winding of less cross-sectional area than that properl reuired to carry such ilux, substantial y as escribed.

8. A lifting-magnet constituting a comlete article of manufacture and constructed.

orl the simultaneous trans ortation of a number of detached pieces o magnetic mal terial, said magnet including a frame. of magnetic material and anannular Winding held to the under side thereof, said frame having a. recess in the center of its under sideJ substantiall `as described. i

9. A ifting-magnet constituting a com- ?lete article of manufacture'and constructed .the simultaneous trans ortation .of a

number of, detached pieces o magnetic materlal, said ma etV including a plate of magnetic material aving a recess in the center of its under. side, a Winding substantialljr com centric With said recess, and meansfor holdmg said winding to the plate,substantiallyV y 

